Archive for July, 2008
Lamarckian Genetics
July 29th, 2008
In the high and far-off times of the 1790s, O Best Beloved, there lived along the shores of the great green greasy Seine River a biologist by the name of Jean-Baptiste Lamarck.
Lamarck was one of the first scientists to explain the differentiation of species by evolution. In his version, traits that parents acquired during their lives were passed along to their children. Thus, a giraffe that had to stretch to eat the leaves at the tops of trees passed down its lengthened neck to its offspring, and a talented human musician who practiced very hard would have more musically-inclined children.
This was some pretty clever thinking for the time, and fit in neatly with the later Victorian passion for self-improvement. Once Mendel & Co. determined the actual mechanism of genetics, though, the whole thing kinda broke.
Some of Lamarck’s ideas were revived in the 1930s in the Soviet Union as Lysenkoism, the theory of genetics upon which the USSR based its agricultural research. Famines resulted. =(
Mamihlapinatapai
July 14th, 2008
Mamihlapinatapai is a word from the Yaghan language of Tierra del Fuego, listed in The Guinness Book of World Records as the “most succinct word,” and is considered one of the hardest words to translate. It describes a look shared by two people with each wishing that the other will initiate something that both desire but which neither one wants to start. This could perhaps be translated more succinctly as “eye-contact implying ‘after you…’”. A more literal approximation is “ending up mutually at a loss as to what to do about each other.”
English fails for not having a word like this.
Emperor Norton
July 9th, 2008
Norton the First, by the grace of God, Emperor of these United States and Protector of Mexico, was essentially a hobo king. After a failed business venture he lost his mind and spent 21 years issuing edicts to the people of San Francisco. He was apparently a benign and well-loved ruler.
Norton spent his days as emperor inspecting the streets of San Francisco in an elaborate blue uniform with tarnished gold-plated epaulets, given to him by officers of the United States Army post at the Presidio of San Francisco. He also wore a beaver hat decorated with a peacock feather and a rosette. He frequently enhanced this regal posture with a cane or an umbrella. During his inspections, Norton would examine the condition of the sidewalks and cable cars, the state of repair of public property, and the appearance of police officers. Norton would also frequently give lengthy philosophical expositions on a variety of topics to anyone within earshot at the time.
The Museum of San Francisco maintains a list of decrees issued by Norton. Example:
July 25, 1869 – Decree from Norton I that San Franciscans advance money to Frederick Marriott for his airship experiments.
Norton also printed his own money, which was eventually accepted by many San Francisco businesses.
Glottochronology
July 7th, 2008
Linguistics + Math + History = Glottochronology. YES.
Glottochronology refers to methods in historical linguistics used to estimate the time at which languages diverged, based on the assumption that the basic (core) vocabulary of a language changes at a constant average rate. This assumption, originally put forward by Morris Swadesh, is based on an analogy with the use of carbon dating for measuring the age of organic materials, in that a “lexical half-life” is estimated. The method estimates the length of time since two or more languages diverged from a common earlier proto-language, by counting the number of words that have been replaced in each language. This then yields an estimated date of origin for those languages.
For example, in an attempt to measure how long Easter Island had been isolated, glottochronologists measured the divergence between the Rapa Nui language (spoken on Easter Island) and the language of the neighboring island of Mangareva and used that difference to estimate the amount of time that must have passed since those two languages had diverged. Neat!
Phospholipid Bilayers
July 5th, 2008
A cell’s membrane is mostly composed of phospholipids, tiny molecules shaped like double-tailed comets. The head of a phospholipid is hydrophilic (that is, it’s attracted to water) and the tails are hydrophobic.
In a cell membrane, phospholipids are arranged in double-wide sheets called bilayers. This allows the tails to hide inside the sheet, away from water.
So, here’s the neat part. If you dump a vial of phospholipids into a beaker of water and mix them up, the phospholipids will spontaneously form membranes! Little spheres called micelles are most common, but the phospholipids also form liposomes, which are basically simple cell membranes. I love when really simple rules give rise to complexity.
Practically speaking, this is how soap works! Soap is made out of fats (lipids) which surround particles of dirt in a micelle. The hydrophobic tails of the lipids attach to the dirt, and the hydrophilic heads are attracted to water, so the micelle can be rinsed away.
Hurray for science!